Bit-gage.



' Y R. S. MoMILLEN.

BIT GAGE. APPLIOATION FILED JULY 6, 1912.

1,105,154. Patented July 28, 1914.

'ITNES-iZM 8 mm n THE NORRIS PETERS C0 PHOTO-LITHO.. WASHINGTON. D. L1

' provements in Bit-Gages,

ROBERT s. McMILLEN, or PITTSBURGH, PENNSYLVANIA.

BIT-GAGE.

Specification of Letters Patent.

Patented my 28, 1914..

Application filed July 6, 1912. Serial No. 708,049.

To all whom it may concern Be it known that 1, ROBERT S. MoMInL iN, a citizen of the United States, and residing in the city of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented or discovered new and useful 1mof which the following is a specification.

My invention consists proved gage for bits, augers, boring-devices.

The purpose is to automatically limit the depth of the hole made in the material being bored, as, for instance, in countersink, 1n

Tfly object is to provide an inexpensive, yet eflicient and durable device, which may be easily installed, adjusted or removed, and which requires no special form of bit nor any change or alteration in the same.

My object is further to provide a gage which presents no exterior projections or irregularities which might catch on the clothes of the workmen, causing in ury, as frequently happens in devices now in use for this general purpose.

In the accompanying drawings, Figure 1 is a side elevation of the lower end of a bit provided with my gage; Fig. 2 is a vertical section of the gage along the line IL-II in Fig. 1, and Fig. 3 is a top plan view of the of a new and imdrills and other 'e. he following is a detailed description of: the drawings.

A represents the bit. In the drawings the same is shown as a wood auger as my invention is especially intended for use in wood-working, but it is also applicable to the boring of metal or other materials.

1 is the worm of the bit.

B is a cylindrical collar through which the bit is inserted. Said collar is upwardly tapered at the top and provided with vertical splits, 2-2, extending down from the top thereof. The upper or tapered portion of the collar is provided with an exterior spiral thread 3 upon which is mounted a clamping-nut C preferably provided with spanner-holes 4-4. The lower portion of the collar B is cut away at opposite sides as at 5--5 forming slot in said collar extending upward from the bottom thereof. The

portions of the collar between said cut-away portions constitute legs 6, 6.

The use of my invention is as follows:

The bit A is inserted through the collarB- until thelower extremities of the legs 66 mark on the bit the desired depth of bore. The clamping-nut O'is now tightened on the thread 3 until the collar is clamped tightly in place. The bit is then placed upon the material and rotated in the usual manner, sinking into the material until the legs 6-6 contact with the surface of the material being bored and prevent further entrance of the bit into said material. Continued rotation of the bit will not result in deepening the boring. The chips or cuttings from the material bored will escape during the boring through the cut away portions 5-5.

Where a large number of borings are to be made in the same piece of material, as in railway-car manufacture, a plurality of bits are frequently mounted in the same machine and power-driven. In such cases the provision of reliable means for limiting the depth of bore of the individual bits is very important, otherwise the loss of or damage to material owing to inattention of the workmen would be very great. My device is particularly applicable for this purpose as the prolonged rotation of the bits after the desired depth is reached wili not result in further deepening of the holes.

Gages have been used which present pro jecting pins or irregularities which frequently cause injury to the workmen. My gage presents no such features and therefore avoids such accidents. The gage is readily installed, removed or adjusted on the bit by loosening the clamping-nut and sliding the collar along the bit. There are no parts to get out of order or to be easily lost and adjustment before being issued to the workmen who are unprovided with spanners to loosen the clamping-nut. The gages are therefore practically tamper-proof.

What I desire to claim is A bit-gage comprising a collaradapted to encircle the bit and having integral, depending legs adapted to encounter the material being the gages may be locked at proper bored, and spaced sufficiently I to allow escape of the chips therebetWeen, Signed at Pittsbu the upper portion of said collar being day of July, 1912. tapered and threaded exteriorly and split rgh, Penna, this 2nd longitudinally, and a clamping-nut adapted 1 ROBERT MOMILLEI" 5 to travel on said threaded portion and com- Vitnesses:

press said split portion to clamp the collar EDWARD A. LAURENCE,

upon the bit. LUCY DORSEY Luis.

Copies of this patent may be obtained for five cents each, by addressing the a 1 Washington, D. C.

Commissioner of Patents, 

